Control mechanism



Nov. 7, 1950 E. P. BULLARD, IIL

CONTROL MECHANISM 6 Sheets-Sheet 1 Filed June 24, 1944 INVENTDR EUwA Rn B BULLARDJZZ A DRNEY Nov. 7, 1950 E. P. BULLARDJII 2,528,736

coNTRQL uEcHAmsu Filed June 24. 1944 e sheets-sheet 2 P ig. 3

INVENTDR En WAR DEB ULLARDJII Nov. 7, 1950 E. P. BULLARD, 111

CONTROL MECHANISM 6 Sheets-Sheet 3 Filed June 24, 1944 INVENTDR WWW Nov. 7, 1950 E. P. BULLARD, nl

CONTROL MECHANI'SM 6 Sheets-Sheet 4 Filed June 24, 1944 INVENTUR BY EDWARD P. B uLLAHn QMW/ E. QN Gm o mmm N QN Nov. 7, 1950 E. P. VBuLLARl-J, m

CONTROL HECHANISlI Filed Jun 24, 1944 6 Sheets-Sheet 5 N VE NT UR EDWARD P. BuLLARDlH Q@ E@ E@ im@ m.. /mwm E Nov. 7, 1950 Filed June 24, 1944 FUNCTION CDNTHDLDHUM DEVELCIPED E. P. BULLARD, In 2,528,736

coNTRoL MEcHANrsu 6 Sheets-Sheet 6 En WA RD E BULLQRD, III

ATTCIRNEY above.

Patented Nov. 7, 1950 CONTROL MECHANISM Edward P. Bullard III, Fairield, Comi., assignor to The Bullard Company, a corporation of Connecticut Application June 24, 1944, Serial No. 541,986

22 Claims.

This invention relates to controls for apparatus capable of producing a relatively large number of functions. Particularly, it relates to a control mechanism that will automatically select, in any order within a cycle of operation any one or more functions of which an apparatus is capable, while providing separate means for very accurately determining the extent of each of said functions.

Ordinarily, the accuracy that can be obtained inthe operation of machine tools, and particu- I larly in the automatic-cycle operation of machine `the member such as trip switches. Machine tool operation requires an accuracy, in stOppIlg the movement of a tool, in the nature of .0005 of an inch, Not only must such accuracy be produced,

-but it must consistently be maintained regardless Aof the rate at which the tool is being fed. Prior known electrical equipment including contact- -making circuits for controlling the movement of a tool fails to produce accuracies of the order Vrequired in machine tool control as set forth This is primarily true because detrimental arcing between critical contacts of such equipment produces a molten conditionon the contact surfaces, thereby changing the point at Y, which such contacts subsequently make the circuit. In order to overcome this condition, by reducing to a minimum the duration of such detrimental arcing, prior known switches employ a quick, wide separation of the contacts when it is ,desired to de-energize such a control circuit.

A wiping action between contacts while separating them is also employed to smooth the rough contact surface caused by the molten condition due to detrimental arcing. These prior known switches often employ metal-exing members ,that are operated in response to tool movement y for producingthe quick wide separation of conytacts.

rlfhe accuracy of such constructions is limited because the metal-flexing members fail to respond at exactly the same point of tool movement upon repeated operations under the same conditions.

Objects of the present invention include the provision of a control mechanism for cycle-operating apparatus of thetype that involves means adapted repeatedly to be moved along one or more paths in any order and for any distance; the provision of a control mechanism for a machine including means capable of performing a multiplicity Aof functions, wherein the control is adapted to render said means fully automatic, but still preserve its manual operativeness; and the provision of a control mechanism for a machine of the type that involves means adapted repeatedly to be moved along one or more paths for different overlapping distances within a cycle of operation.

Other objects of the invention include the provision of an electrical control circuit that can be energized repeatedly by the engagement between movable contact elements at exactly the same point relatively to each contact element; the provision of such an electrical control circuit wherein the surfaces of the energizing contact elements are not altered by continued repetitive use, by detrimental arcing or wear due to a sliding action; the provision of such an electrical control circuit in which the energizing contact elements ycan be brought into engagement as slowly as desired to energize the circuit without detrimental arcing; the provision of such an electrical control circuit that is de-energized before the contact elements are separated that are employed for energizing it; the provision of an electrical control circuit including a plurality of circuit-energizing contacts, each including movable contact elements, that are successively connected into the circuit and each of which embodies the above-noted characteristics; theprovision of such an electrical circuit that is energized by the engagement between one set of contact elements and de-energized by the separation of another set of contact elements, and in which the contact elements of the first set vare separated after the separation of the elements of the second set and the provision of an electrical control circuit for a multi-function apparatus wherein the duration of each function is determined by the engagement of separate circuitenergizing contact means that are successively connected into the circuit and in which said circuit embodies all of the above-noted characteristics.

Other objects include the provision of apparatus capable of a relatively large number of functions which embodies means for selecting in any order, a relatively great number of any of said functions within a cycle of operation and including separate electrical switch-means for each function within said cycle of operation; the

Edog'at right angles to 'the y =movement between the switch and its dog; the provision of such an apparatus in which each 3 provision of such an apparatus in which each switch is arranged in cooperative position relatively to a separate switch-actuating dog, and in which cooperation between the two is responsive to a function of the apparatus; the provision of such an apparatus wherein the relatively great number of switches and dogs is so constructed that a maximum number is included in a minimum of space; the provision of such van apparatus wherein the switches are actuated by relative movement between them and their dogs in response to the functions of the apparatus; the provision of such an apparatus in which each switch includes single contact means having movable contact elements operable to energize a circuit by the action of a dual-directional-motion actuator; the provision of such ran apparatus wherein each switch is so constructed that cooperative abutting engagement between it and its dog occurs completely within a surface of the direction of vrelative and switch-employs means for multiplying the rela- *t'ive-motion between it and its dog and transmits :such rvamplified motion to the single-contact means through rigid compression members.

Another specific obect of the invention is the provisionvof a control Vfor a machine tool of the pre-settable cycle-operating type involving cons trol means that is moved from position to position for selecting successive functions within a cycle of operation, and wherein the functions are 'terminated independently of the movement of the vcontrol means.

The above, as well as other objects and novel features ofthe invention, will become apparent from-the following specification and accompanyingv drawings, in which:

Figure 1 is a 'front elevational view of a machine tool embodying the principles of this invention;

Figure 2 is a side elevational view of the machine tool shown in Figure l;

`'Figure 3fis a partial top plan view of the machine tool shown in Figures 1 and 2;

Figure 4 -is a sectional plan view taken substantially along line 4-4 of Figure 2;

Figure 5 is a sectional elevational view taken `substantially along line 5-5 of` Figure 4;

lFigure 6 is a sectional plan view taken along line 6-8 of Figure 3;

Figure 7 is a sectional plan view taken along line 1-'1 of Figure 1;

Figure 8 is an enlarged sectional view taken along line 3 8 of Figure l1;

Figure 9 is a plan view taken along line 9-9 of Figure 8;

Figure lOis an elevational view taken along line lil- I0 of Figure 8;

Figure 11 is a detail of the apparatus shown in Figure 8;

Figure 12'is a schematic layout of the essential features of the invention;

Figure 13 is a sectional view taken substantially `alongline l3-I3 of Figures 2 and 4;

Figure 14 is a sectional View taken substantially along line lll- M of Figure 13;

Figures 15, 16, 17 and 18 are views showing the position of the tool turret at successive points in a cycle of operation;

Figure 19 shows an enlargement of a `portion of Figure 1 with adjustable means set to cause the apparatus to produce a cycle of operation; and

Figure 20 is a developed view of the function control drum with adjustable means set to cause the apparatus to produce a cycle of operation.

Referring to Figures 1 and 2, the principles of the invention are shown as applied to a verticalturret lathe including a standard Sl on which is mounted a horizontally-disposed work-supporting table W adapted to be rotated at'aplurality of speeds by a headstock transmission Tw. The standard S is adapted also to support a cross rail C on which is mounted a turret head Ht that is adapted to be moved along a pair of intersecting paths by the operation of a feedworks transmission Th that receives its power from the headstock transmission Tw.

The movement of the turret head Ht along either of its paths, as well as its indexing movement to present different tools to the work, are adapted automatically to be controlled by the operation of a control mechanism F. The control mechanism F selects and initiates 'the Tfuncti'ons ldesired of the turret -head Ht. An auxiliary `co'n- 'to that shown and disclosed in yPatent No.

1,172,341, dated February 2.2, 1916, 4to Edward PBullard.

The standard S includes vertically-disposed bearings 24 and "25 along which 'the cross rail `C is adapted to be moved. The cross rail `Cincludes two horizcntally-di'spose'd bearing surfaces V2t land"2l along which asaddle '2'8 is adapted to be moved. The saddle 28 includes vertically-disposed bearings for receiving a slide 29 that is adapted to be moved fatfan angle tothe movement of the saddle 28. Horizontal movement of the saddle `28=is effected by therotation of a screw'l'rnoun'ted in-the'c'ro'ss rail-C. Movement of the slide '29 is effected by 'the rotation of a splined shaftl parallelfto, and also mounted-on the cross rail C. The outer end of screw 353 supports a worm gear 32 and a-similarworm gear 3-3-is xed tothe outer end of splined shaft 3l. Hand cranks Sii and '35 areprovided adjacent the gears'Z and'3`3lf'or manual-ly'turning the screw 30 and theshaft 3i. A worm 36 is located between the two gears 32 and-33. It is adapted to be rotated in either direction rat'any one of aplurality of speeds by the feedworks transmission Th. Accordingly, it 'is only necessary to move the worm SSlu'pwardly into lengagement with the gear 33 in order 'toprovide movement 'of slide 28 along thebearings formed in thesad- '.tion. A clutch 40 is located between the gears 38 and 439 and it is splinedto the shaft `3'I. `Both gears 38 and 39 mesh with a bevel gear 4|. The gear 4| is fixed to a shaft 42'. Spur gears 43 and 44 are fixed to the shaft 42 and they mesh with corresponding gears 45 and 46 journaled on a shaft 41. TheV shaft 41 is hollow and a diving key 48 extends thereinto. The key 48 is adapted to be moved from engagement with gear 45 to engagement with gear 46 selectively for a purpose to be described later. Spur gears 49, 56, 5| and 52 are xed to the tubular shaft 41. Spur gears 53, 54, 55 and 55 are journaled on another shaft 42. The portion of shaft 42 on which gears 53 to 55 are journaled is of tubular construction for receiving a diving key 51. A bevel gear 58 is xed to the end of shaft 42 and it meshes with a bevel gear 59 xed to the worm 36. From the foregoing it is evident that worm 36 may be rotated in either direction at any one of eight different speeds depending upon the positions of diving keys 48 and 51 and clutch 40.

Referring to Figure 12, the screw 39 threads into a boss 69 on the back of the saddle 28. The splined shaft 3| supports a worm 6I for sliding movement therealong. The worm 6| meshes with a worm wheel 62 on the back of saddle 28. The worm 62 is xed to a shaft 63 that also supports a spur gear 64 in mesh with a rack 65 on the back of the slide 29. The Shaft 63 is journaled in bearings on saddle 28. Rotation of screw 3U, therefore, moves saddle 28 and slide 29 horizontally and rotation of splined shaft 3| moves slide 29 along the bearings formed therefor in saddle 28. Accordingly, moving worm 36 into engagement with the gears 32 and 33 will cause the movement of head Ht along its respective paths in either direction at any one of eight different speeds depending upon the positions of clutch 40, key 48 and key 51.

A housing 66 is attached to the end of the cross rail C opposite that end which supports the feed- Works Th. This housing is adapted to support continuously-driven oppositely-rotatable means that is adapted to be connected to a-nd disengaged from the screw 39 and the splined shaft 3| by the selective operation of rods 61 and 68. These rods are axially movable by the oscillation of crank arms 69 and 19. This construction provides means for moving the turret head Ht along either of its paths at relatively fast traverse speeds.

Referring to Figures 1 and 2, the crank arms 69 and 19 are adapted manually to be operated by hand levers 1| and 12. These crank members are also adapted to be hydraulically actuated by pistons within cylinders 13 and 14. The pistons within these cylinders are connected to the crank members 69 and 10 by the connecting rods 15 and 16, respectively. The worm 36 ,is adapted manually to be moved into and out of engagement with gears 32 and 33 by the hand lever 11 fixed to a connecting rod 18 (Fig. 2) which latter is connected to a piston in a cylinder 19. Referring to Figures 2 and 12, the reversing clutch 40 is adapted manually to be moved by a hand lever 80 fixed to the clutch 40. Clutch 40 is adapted hydraulically to be actuated by a piston within a cylinder 8| which is connected to the clutch 40 by a link 82. The diving key 51 is adapted manually to be moved by the hand lever 83, While the diving key 48 is manually operable by the hand lever 84.

Referring to Figure 12, the piston and cylinder constructions 13, 14, 19 and 8| are the same and, therefore, only one will be described. The cylinder 13 includes a dividing partition 85 that copiston 81 includes end portions that extend through the partition 85 and the end portion 86. A rod 88 fixed to the piston 81 extends beyond the partition 85 into another chamber of cylinder 13. Oppositely-disposed discs 89 and 96 are mounted on the rod 88 for free movement relatively to said rod. A nut 9| is screwed onto the end of the rod 88 in engagement with the disc 99. The disc 89 abuts against a shoulder 89 between, rod 88 and the one end portion of piston 81. Fluid under presssure is adapted to be selectively admitted to opposite faces of piston 81 through conduits 92 and 93. Constant pressure is adapted to be supplied through a conduit 94 to the chamber of cylinder 19 that contains the discs 89 and 99. The effective pressure-area of the discs 89, 99 is less than the effective pressure-area of the piston 81. Consequently, admission of pressure to the cylinder 18 through either of the lines 92 and 99 will cause the piston 81 to move within the cylinder 13. Removal of pressure from both lines 92 and 93 will effect the instantaneous centralization of the piston 81 within the cylinder 13. This construction provides means for positively moving the cranks 69, 1li, clutch 49 and worm 36 to their active positions and causes neutralization of each of these elements upon removal of the pressure from the corresponding pistons thereof.

r'he diving keys 48 and 51 are adapted hydraulically to be actuated by cylinder mechanisms 95 and 95. Referring to Figure 6, the cylinder mechanism 96 is designed to selectively move the key 51 to any one of four positions so that either of gears 53, 54, 55 or 56 may be keyed to the shaft 42 for imparting a specic speed of lrotation to the worm 36.

Referring to Figure 6, the cylinder mechanism 96 includes an outer cylinder 91 having fluid conduits 98, 99, |69 and lill. 1t includes an end abutting member |62 that is fixed within the `cylinder v91 by a pin |93. At the other end of the cylinder 91 a plug |94 is attached through which the lever 84 extends. Centrally of the cylinder 91 a sleeve |95 is fixed by a pin E96. Another abutting portion |01 is fixed in the cylinder 91 by a flange |98 that engages a shoulder |99 in the cylinder 91 and which portion E91 is held in place by the plug |94. A movable piston member I9 is located between the fixed abutment member |92 and the xed sleeve |95. The piston member |19 is adapted to abut a flange l l l formed on the key 51. Another movable piston l i2 is located in the cylinder 91 between the fixed sleeve E95 and the abutting member 5B1. The construction and arrangement of the parts are such that admission of uid under pressure to the conduit 98 causes the movement of the key 51 rightwardly, as viewed in Figure 6, until the flange Il! engages the piston member |2 and forces the latter into abutting relation with the member |61. This locates the key 51 such that spur gear 58 is keyed to the shaft 42. Simultaneous admission of fluid under-pressure to the conduits 98 and |99 will cause the piston member ||2 to move into engagement with the right-hand end of fixed sleeve |05 with the flange i I in abutting relation to said piston l2. This will locate key 51 such that spur gear 55 is keyed to the shaft 42. Simultaneous admission of fluid under pressure to the conduits |9| and 99 will cause the movement of key 51 leftwardly until flange abuts against piston |'|9 and piston H9 abuts against the left-hand end of sleeve |85. This condition will locate key 51 such that spur gear54 is keyed to shaft 42.

7 Finally, admission of fluid under pressure to conduit alone will move the key 5l leftwardly such that flange abuts piston |||l and piston HS abuts member |82. This condition will locate key such that spur'gear 53 is keyed to the shaft 42.

Referring to Figure 7, the cylinder mechanism 95 includes a :cylinder IZ within which a differential piston B3 is adapted to be reciprocated. The piston H3 is xed to the diving key d8. The cylinder H2 is provided with :conduits Ill and H5. The construction and arrangement of the parts are such that admission of fluid under pressure to conduit H13 only, moves piston ||-3 rightwardly, as viewed in Figure '7, positioning key 48 such that spur gear it is keyed to shaft 4l'. Release of pressure from @conduit iii causes piston ||3 to move leftwardly, as viewed inV Figure '7, such that spur gear i5 is keyed to shaft All" because conduit i 5 is always under pressure as will be explained later.

Referring to Figure 12, uid under pressure is adapted selectively to be supplied to the piston mechanism 8| through conduits H6 and Hl. Fluid pressure is adapted to be suppliedl to the piston mechanism ld through conduits ||8 yand H9. Fluid under pressure is adapted to be supplied to the piston mechanism le through conduits l2@ and |2|. Fluid under constant pressure is adapted to be supplied to piston mechanisms 8|, M and lg through conduits |22, |23 and |24, respectively. This constant pressure iluid is supplied to the conduits |22, |23 and |2i, as well as to the conduit 9d by a pipe |25 that leads from a main source of uid supply P through a duct |26 and a valve |21.

Conduits 92, 93, 98, 99, |88, ||l|, Mil, H5, H6, H8, HS, andv |2| are adapted to be supplied with iiuid under pressure from the main source P by a pipe |2S that leads from valve I2? and is connected to an elongated valve bodyY |23. The valve body |29 is provided with a centrallydisposed longitudinally extending passage |33 throughout its length. It is also provided with a plurality of transversely-disposed valve chambers of identical construction within which are located valve plungers |3| to Mii, inclusive, for conduits 92, 93, 98, S9, lill, i-l, Ht, |ll, H3, Us, |2 and |2|. Valve plunger Mid is employed as a spare and is not shown connected to a conduit. Since all the valve plungers |3| to MM Iare identical, only plunger |3| will be speciiically described. It comprises a valve stem M5 having a valve head M6 at its lower end and an upper head I'i at its upper end. The area of the head M5 is substantially less than that for the head il. Consequently, the constant supply of uid under pressure within the valve body |29 maintains the plunger |3| in its upper position. With plunger |3| in its upper position, the lower head me prevents the passage of fluid under pressure through a discharge duct m8 which is connected to the conduit H8. Upon downward movement of the plunger |3|, the head M5 thereof movesinto a chamber M9 having an exhaust |50, whereupon fluid from line |28 may pass said head and empty into duct IM.

The conduits H8, llt, 92 and 93 control the operation of the arms l and 9, respectively, for rendering effective the quick traverse movement of the head Ht. During a machining operation it is necessary to provide a dwell at the end of any feeding operation for the purpose of cleaning'up the work. Accordingly, time delay mechanisms |5|, |52, |53 and |54 are provided between the valve body |29 and the conduits ||8, H9, 92 and 93. Since each of these mechanisms is identical, only the' mechanism |5| will be specically described. Referring to Fig. 5, the time delay mechanism |5| includes a differential piston mechanism comprising pistons |55 and |55 operating in a diierential cylinder |51. A station ary rod |53 intersects the cylinder |51 and serves as an abutment against which pistons |55 and |56 are adapted to rest. The piston |56 is provided` with a piston rod ld to the one end of which a head I6@ is attached, and to the other end of which a head lt! is attached. The piston |525 includes a portion |62 of reduced diameter which forms with a collar |3 a chamber it. The fluid under pressure passes from the pipe |33 into the valve body |29, Fig. 12, and as shown in Fig. 5, it supplies fluid pressure to a duct |65 having an opening |66 into the chamber |5| and an opening |t'| into a chamber formed by the upper and lower heads mi), ||3| of the piston |55. A duct |63 extends from the duct |55 to the chamber in which head hit of plunger |3| acts. rihe construction and arrangement of parts are such that fluid.- pressure at all times tends to move the pistons |55 and |56 into engagement with abutment |53 and also supplies through duct |68, fluid under pressure for operating the time delay mechanism. inwardY movement of the plunger 53| moves the head Mt such that the fluid under pressure from duct |58 passes through duct MiB into the space between pistons |55 and |55. The cross-sectional area of piston |55 is substantially greater than that of the head itl for piston ist; Consequently, piston |55 moves outwardly away from the abutment |55, while the piston |56 remains in engagement therewith. When piston |55 has moved outwardly its maximum extent, that is, when its head has engaged the collar |53, piston its moves outwardly, whereupon its head |63@ opens duct |67 to the outlet lt@ which latter is connected to the conduit iid. Accordingly, upon each downward movement of the plunger ii, there will be efected a time delay before the fluid under pressure from line |2| passes to conduit H8.

The plungers |S| to Mii, inclusive, Fig. 12, are adapted selectively to be depressed by the step-bymstep rotation of a function drum il@ about a horizontal axis. The drum Vid is provided with a series of circumferentiallyedisposed openings forming means whereby dogs V52 can be attachedto said drum. There is a series of such holes |l| in line with each of the plungers |3| to Ulli, inclusive, as well as other such series of openings for purposes to be described later. The drum Hd is shown in the form of a cylinder having trunnions |73 and VM which are supported in the usual manner in bearings in the housing of the function control mechanism The drum Wl is adapted to be indexed a predetermined number of degrees about its horizontal axis intermittently so that the dogs located on the drum in a longitudinally-disposed row or openings il' will become eiective to depress the selected plungers I3! to idd, thereby to operate the machine in a manner to be described later. Ratchet wheels |15 and iii are xed to the trunnion |'F3 of the drum Hij. The ratchet wheel Vit is employed to index the drum ITU, while ratchet wheel |16 serves asa retaining means for locking the drum Vl@ in each of its indexed positions.

Referring to Figs. 13 and 14, the ratchet wheels |15 and 76 are actuated by a piston mechanism |11. It comprises a piston and valve body 18 having a cylinder |19 within which a piston |80 is adapted to be reciprocated. The piston |80 includes a tailrod |8| having an adjustable lock nut |82 fixed to its end for limiting the movement of the piston |80 in one direction. A piston shaft |83 extends from piston |80 in a direction opposite that of the tail rod ISI and supports a pawl |84 pivotally mounted to it by a pin |85. The forward end of the shaft |83 is provided with an elongated slot |86 through which a pin |81 extends that is anchored into the housing |18 to prevent rotation of the shaft |83 and piston |80. Forwardly of the slot |86, the shaft |83 is reduced in diameter and passes freely through a bushing |88 frictionally held within a bore |89 of the housing |18. The end of the reduced portion of shaft |83 has fixed to it an adjustable lock nut |99. The construction of the forward end of the shaft |83, as well as that of the sleeve |88, together with their functions, will be described later. The pawl |84 is adapted to be forced into positive driving engagement with the teeth of ratchet wheel by a piston mechanism |9|, not only to insure positive meshing between the two, but also to prevent overtravel of the ratchet wheel |15. The piston |9| is mounted for reciprocation in a bore |92 within the housing |18. The piston includes a reduced portion |93 within a chamber |94 of the bore |92 and around which a compression spring |95 is located.

Referring to Fig. 14, the ratchet wheel |16 is adapted to be engaged by a spring pressed detent |96 that is urged into locking engagement by a compression spring |91 within a bore |98 of housing |18. The detent |96 is provided with a piston head |99 against which spring |91 reacts. Fluid under pressure is adapted to be admitted to the bore 98 above the piston |99 intermittently in timed relation with the operation of the piston |80 for releasing the ratchet wheel |16 at the time ratchet wheel |15 is indexed by the piston |80. Fluid under pressure is adapted intermittently to be supplied to the inlet 200 from the conduit 2|4, Fig. 12. Inlet 200 is provided with a branch that connects with conduits 202, 203, 204, 205 and 206, the last of which enters the chamber |19 within which piston |80 is adapted to be reciprocated. Referring to Fig. 14, a branch conduit 208 extends from the conduit 200 to the bore |98 above piston |99 therein. Constant pressure is adapted to be supplied to an inlet 209 from the source P through a branch 209 (see Fig. 12). This inlet 209 is connected to the chamber |19 on the opposite side of the piston |80 from that to which inlet 206 admits fluid under pressure. The effective area of the piston |80 that is subjected to the constant pressure from inlet 209 is substantially less than that subjected to the intermittent pressure from inlet 206. Accordingly, admission of the pressure from inlet 206 moves piston |80 to the left, as viewed in Fig. 13, and upon release of such Dressure, piston |80 moves rightwardly due to the constant pressure from inlet 209.

Since the conduit 203 crosses bore |94 beneath piston |9|, intermittent supplying of fluid through the conduit 200 forces the piston |9| upwardly thereby moving pawl |84 into positive driving engagement with the teeth of ratchet |15. At the same time, this same fluid passes from inlet 200 through branch 208 to the chamber |98 above piston |99, retracting the detent |96 thereby releasing the ratchet wheel |16. At

10 the same time, this same fluid under pressure passes through conduits 20|, 292, 203, 204, 205 and inlet 206 to the right-hand side of piston |80, as viewed in Fig. 13, causing the piston |89 to move leftwardly to index the ratchet wheelv |15 and with it function drum |19. Interruption of the fluid under pressure to conduit 200 permits piston to move rightwardly, causes detent |96 to move upwardly into locking engagement with ratchet wheel |16 by spring |91, and removes the pressure from the piston |9|.

Referring to Fig. 12, pressure from a main source P branches olic from the line |26 through a valve 2| 0, lines 2li 2|2, a manually operable valve 2 I3 to be described later, and a conduit 2|4 that is connected to the inlet 290 of the housing |18. The valve 2li? comprises ball members 2|5, 2|6 that are joined by a slender rod 2|1. The balls 2|5 and 2|9 are adapted to seat in a valve body 2|8 to prevent the passage of fluid thereby. rihe construction and arrangement of parts are such that when ball 2|5 is engaged with its seat, ball 2|6 is out of engagement with its seat, and vice versa. Accordingly, movement of the balls 2|5, 2|6 to the left, as viewed in Fig. 12, will permit fluid under pressure to be admitted through lines 2! 2|2, manually operable valve 2|3, line 2|4, to inlet 200 from which it passes to inlet` 206 (Fig. 13) as previously described. Upon release of the force moving balls 2|5 and 2|@ to the left, as viewed in Fig. 12, they will move to the right under the combined influence of the pressure from the source P acting against the ball 2|5 and a spring 284, thereby cutting off the flow of fluid under pressure to the inlet 200. The constant supply of pressure to inlet` 209 is supplied from the branch conduit 209.

From the foregoing, it is evident thatthe intermittent operation of the valve 2li! will cause the intermittent indexing of the function drum |10 to effect the depression of selected of the valves |3| to |44 for controlling the operation of the machine tool. In order to reduce to an absolute minimum the time required to exhaust the valve piston mechanisms 8|, 1li, 19 and 13, means is provided for effecting their exhaust independently of the indexing of the function drum. If the exhausting of these piston mechanisms were effected by the upward movement of the valve members |3| to |44, instantaneous action could not ybe obtained since a definite time interval is required in moving thedrum from one position to the next. Accordingly, the present invention overcomes this difculty by providing a unique valve mechanism between the piston mechanisms 13, 14, 19 and 8| and the valve 'body |29 including the time delay devices |5l, |52, |53 and |54. This valve mechanism is designed to effect instantaneous exhausting of the piston mechanisms 13, `14, 19 and 8| independently of the .action of the inf dexing mechanism for the function drum |19. It comprises an elongated bore 220 within which a plurality of independent piston members v22| is adapted to .be reciprocated for a limited distance. Each of the piston members 22| is identical and comprises a head portion 222 and a stem portion 223. They are arranged in aligned abutting relation. The bore 220 is provided with a plurality of ports 224 to which the conduits H8,A H9, 92, 93', H6, H1, |20 and |2| are connected. It is also provided with a plurality of inlets 225 to which the chambers for valves |3|, |32, |93, |34, |35, |36, |31 and |38 are connected. The bore 220 is also provided with a plurality of exhaust ports 226. The construction and arrangement of parts ployed.

' 11 are such that normally the piston members 22| are in abutting relation, as shown in Fig. 12, with their head portions 222 overlapping or co-vering the exhaust ports 226 and permitting free passage between the valve body |29 and the conduits ||8, H9, 92, 93, H6, ||1, |26 and |2|. Constant pressure is supplied to the left-hand end of the bore 226 through a branch 221 of the conduit |28, normally maintaining the pistons 22| in the position shown in Fig. 12. A branch line 223 of the line 2|| is connected to the right-hand end of bore 229 and acts upon the head 222 of the rightwardmost piston 22|. Accordingly, upon the intermittent actuation of valve 2 9, the piston members 22| will be moved leftwardly such that the exhaust ports 226 will be uncovered and the inlet ports 225 will be covered. When this occurs, the conduits H8, H9, 92, 93, H6, H1, |29 and |2| will be instantly exhausted before indexing of drum |19 will take place by the action of the liuid under pressure in line 2| 4. This construction greatly increases the accuracy of the feed knockout, as well as the traverse knock-out. That is, neutralizing of the feed and traverse clutches and drop worm 39 is instantly accomplished recapable in accordance with the operation of l.

valves |3| to |44. The extent of any function selected by the drum |16 is adapted to be determined by mechanism associated with the movable head Ht. This mechanism is designed to provide a separate function determining means for each function called for by a setting of dogs |12 along a longitudinally-disposed row of openings |1| on `drum |16. It comprises in the present embodiment, switch-trip supporting means 229 to 236, inclusive, one for each of the longitudinally-disposed rows of holes |1| on the drum |10. Although only eight such supporting means and eight longitudinally-disposed rows of dogs |12 on drum |19 are shown, it is to be understood that any number of such supporting means and longitudinal rows of dogs |12 may be em- In practice, it has been found that about forty such supporting means and rows of dogs on drum |19 are adequate. The switch-trip supporting means are mounted on a panel. 231 rigidly attached to the saddle 29 of the machine. Similarly, supporting means 236, 239, 249, 24|, 242, 243, 244V and 245 are mounted on a panel 246 xed to the cross rail C. An arm 241 is fixed to and movable with the slide 29 and includes a right-angularly disposed portion 248 having switches 249 above the supporting means 229 to 236, inclusive. An arm 256 is fixed to, and movable with the saddle 29 along the cross rail C and it includes a right-angularly disposed portion 25| having switches 252 above each of the supporting means 233 to 245, inclusive. The construction and arrangement of the parts are such that movement of slide 29 along the bearings in the saddle 28 will cause the switches 249 to move along means 229 to 236, inclusive, and horizontal movement of saddle 28 will cause the switches 252 to move along the means 239 to 245, inclusive.

Adjustably-mounted dogs 253 are adapted to be located along each of the supporting means 229 to 236 and 236 to 245, inclusive. The switch 249 above means 229 is connected to the switch 252 above means 238 by a common wire 254. .Switches 249 and 252 above means 239 and 239 are connected by a common wire 255. Switches 249 and 252 above means 23| and 240 are joined by wire 256. Wire 251 joins switches 249 and 252 above means 232 and 24|. Wire 259 joins switches 249 and 252 above means 233 and 242. Switches 249 and 252 above means 234 and 243 are joined by wire 259. Wire 269 joins switches 249 and 252 above means 235 and 244. Switches 249 and 252 above means 236 and 245 are joined by wire 26|. The specic construction of the switches 249, 252 and the switch-tripping dogs 253 will be described later. l

Each wire 254 to 26|, inclusive, is connected to a separate contact 263 of a distributor 2,34l that is mounted about trunnion |14 of function drum |16. The contacts 263 are located about the periphery of a non-rotatable cylindrical member 265 of the distributor 269 such that wires 254 to 26| are successively adapted to be contacted by a brush arm 266 fixed to and rotatable with the drum |16. A binding post 261 is provided with the group of contacts 263 as the no-function position of the drum. The binding post 261 is provided with a line 268 having a manually operated push-button 269 between the binding post 261 and a ground connection for the purpose of initiating a cycle of operation as will be described later. The brush arm 266 includes a contact member 219 that is maintained in rubbing engagement with a fixed contact 21| to which another binding post is fixed and mounted in the non-rotatable cylindrical member 265 of distributor 264. The contact 21| is provided with a conductor 212 that extends through a switch 214, thence to a compound switch mechanism 215 adjacent the drum,-

indexingmechanism. The switch 215 includes a normally closed contact 216 and a normally open contact 211. The conductor 212 is connected to one pole each of the switches 216 and 211. The opposite pole of the switch 211 is grounded and the opposite pole of the switch 216 is connected by a conductor 213 that extends to and is connected with a source of electrical energy G. The source of energy G also is in series connection with a solenoid 219, the opposite side of which is grounded. The solenoid 219 is adapted upon energization to cause the pivoting of an arm 266 about a pivot 28| to operate the valve 2|9.

Operation of the switches 249 and '252 grounds the wire 254 to 26| that is connected to'it, to create a circuit through the solenoid 219. Assume that brush 266 is in contact with the binding post 263 for the conductor A259 that is common to the switches 249 and 252 forv the switch-trip supporting means 234 and 243, ref spectively. Further, assume that the head Hu is moving along one of its paths, for example, that dened by the bearings in the saddle 29. Since head Ht is not moving horizontally, no dog 253 will be employed on means 243. When the switch 249 above means 234 engages the dog 253 thereon, said switch will operate so that current will ow from the generator G through the conductor 218, the normally-closed switch 216 to the conductor 212, the normally-closed portion of switch 214, the Contact members 21|, 219, the brush 266, binding post 263, conductor 259, switch 249, thence to the ground C on the frame of the machine, back to the one side of the solenoid 219 and finally to the generator G. Energization or" the solenoid 219 will cause the valve 2 i6 to operate such that the balls 2|5, 215 move leftwardly, as viewed in Fig. 12, whereupon pressure from the source P is adapted to pass the ball 2|5, enter the conduit 2 I l and move the piston members `22| leftwardly, thereby to eX- haust all of the lines H8, ||9, 92, 93, IIS, I|1, |28 and |2i. Such action will immediately neutralize all of the operating elements of the feedworks Th. At the same time, this fluid under ressure will pass through branch 2 I2, valve 2 I3, conduit 2|4, and effect the indexing of the drum to its next succeeding position. It will be observed, however, that as soon as the drum |10 begins to index, the brush arm 266 moves off the binding post 263., thereby removing the ground C' from the circuit including the solenoid 219. Accordingly, in order to effect a complete index of drum |18, it is necessary to provide a substitute for ground C while the arm 266 is moving between successive binding posts 263. This is accomplished by the normally open switch 211 of the compound switch 215.

Referring to Fig. 13, the normally closed switch 216 comprises a spring pressed detent 288 normally heldin depressed condition by the sleeve |88 within the bore |89. The sleeve |88 is frictionally maintained in position by a spring-friction member 28 I. The normally-open switch 211 comprises a similar spring pressed detent 282 that is adapted to be closed by the movement of the rod |83 of the plunger |89. The rod |83 includes, for this purpose, a cam surface 283 that upon leftward movement, depresses plunger 282 thereby closing switch 211 to provide a ground for C which is eliminated when brush 266 moves off post 263. Continued movement of the rod |83 leftwardly may, therefore, occur causing the member 283 to abut against the one end of the sleeve |88, moving it outwardly and leftwardly so that detent 286 raises, effecting opening of switch 216. This abutting relation between cam 283 and sleeve |88 does not occur until the piston |86 has moved suciently to effect complete indexing of the drum |10, whereupon the switch 216 is opened, de-energizing the solenoid 219 and permitting spring 284 (Fig. 12) to move the balls 245 and 2 I6 of valve 2 !U rightwardly thereby cutting oir the flow of fluid under pressure to the conduit 2li. Interruption of the flow of fluid under pressure through the line 2||, valve 2|3 and line 2 I4 causes the piston |80 to be returned to its normal position by the constant pressure from line 289 that enters the inlet 289 of the housing |18. Accordingly, piston |80 is positioned properly for its next succeeding index.- During this rearward movement of piston |80, nut engages sleeve |88 to return it to a position where it depresses detent 28|! thereby closing switch 216. Just before switch 216 is closed, the portion 283 of rod |83 Vreleases detent 282 permitting ground switch 211 to open.

As previously mentioned, the practical embodiment of the invention employs as many as f-orty or more means 238 that support dogs 253 and an equal number of longitudinally-disposed rows of openings I1! on drum |18. Accordingly, forty or more individual switches 252 are required, one for each switch-trip supporting means 238; and an equal number of switches 249 is also required for the trip-supporting means 229, etc.

Referring to Fig. 8, the uprights comprising frame 245 support the switch-trip supporting means 238 which includes a wire 285 rigidly fixed between the uprights of frame 246, and a wire 286 located in a vertical plane spaced from that including wire 285.

The wire 286 is mounted within openings in the uprights of the frame 246 in parallel relation to wire 285. The wire 286 is adapted to be axially moved for a purpose to be described later. A compression spring 281 surrounds the one end of the wire 286 outside of the frame 246. An adjustable nut 288 is threaded onto the end of rod 286 for varying the compression of the spring 281. The end of rod 286 opposite that supporting spring 281 extends through one upright of the frame 246 and is provided with a micrometer thread 2 89 and a micrometer nut 296. By turning the nut 298, the wire 286 may be axially moved in either direction since the spring 281 maintains a constant tension on the wire.

The dog 253 comprises a relatively narrow rectilinear body having passages 29| and 292 extending through it for the reception of the wires 285 and 286. Lock bolts 293 and 294 are threaded into the lower end of the dog 253. The bolts 293 and 294 abut against the wire 286. Loosening of bolts -293 and 294 will permit the adjustment of the dog 253 axially along the wires 285 and 286 for approximately locating the dog 253 in its correct position. Tightening of the bolts 293 and 294 will fix the dog 253 to the wire 286. With the dog xed to the wire 286, accurate adjustment of the dog 253 relatively to the switch 252 may be effected by turning the micrometer nut 298 on the one end of wire 286. The micrometer thread 289 of the rod 286 that receives the nut 290 comprises lG threads to the inch so that a complete turn of nutv 298 will move dog 253 an amount equal to .025 inch. A dial is provided with each nut 298 of ten equal divisions so that it is possible accurately to move dog 253 an amount equal to .0025 inch, and it is possible to estimate move- .ents of dog 253 of less than .001 inch.

Figures 8, 9, 10 and 11 show one switch 252 in detail with its attending parts. Since all switches 249 and 252 are identical, only one will be described in detail. In the present embodiment of the invention, the switch-supporting members 248 and 25| are moved over their respective switch-trip supporting means and said means remain stationary. Of course, whether the supporting means move or the switch supports move is immaterial, so long as relative motion between the two is provided.

The novel circuit includes a series connection between four essential elements including: (l) a source of voltage, which in the present embodiment is about thirty-two volts, and is represented by generator G, Fig. 12; (2) an electrically operated load device which in the present embodiment is solenoid 219; (3) electrical contacts adapted to be opened repeatedly by substantially an identical action, which comprises arm 266 of distributor 264; and (4) a circuit-energizing contact which, in the present embodiment, is operated in response to the movement of the tool turret and comprises switch 252. The operation of the circuit including these four essential elements must be such that contacts of distributor 264 are rst closed which establishes the circuit as far as the corresponding circuit-energizing contact or switch 252. When the turret head reaches its destination, switch 252 is operated thereby energizing the circuit. Energization of the circuit operates the solenoid 219 which in turn actuates the valve 2|6 supplying uid to piston mechanism |11 which in turn actuates arm 266 to de-energize the circuit. Finally, the circuitenergizing contact (switch 252) is opened only after its corresponding distributor contacts have been opened. The above-described operation of .the 4circuit prevents detrimental arcing of the circuit-energizing ,contact (switch 252), which is the key to the accuracy of the control. Accordingly, the surfaces .of the movable parts of the contact of switch 252 are never altered by melting due to .arcing The member l which supports the switches .252 is composed of insulating material and is iixed to bracket 259 that is moved between the .uprights of the frame 225 in response to the horizontal movement of head Ht. A. metallic switch-supporting body 295 extending throughout the .entire length of the insulating member is rigidly bolted to it. The member 25H is provided with a plurality of holes 296 that extend through the member 25'l and are aligned as shown in Fig. 9. The metallic body 295 is provided with an identical series of holes or bores 29? that are slightly larger in diameter, but axially aligned relatively to the holes 292. A plunger 2953 is located in each of the holes 297 and includes a stem portion 299 that extends upwardly through the hole 295 in the insulating block 225i. A coil spring 359 is located within the holes 29'i between the block 2.5i and a shoulder 3iil on the plunger 29B. The lower end of the plunger 2,98 rests on an actuating member 322. The actuating member 322 is shown in Fig. ll

comprises a hat plate having arcuate portion 322 joined by tangential portions 322, 325 on each side thereof. The actuator is also provided with trunnions 325, 3M that extend through beyond the actuator 322 for equal distances on each side of said actuator. The lower portion of the body 295 is provided with a series of slots 29.5 each oi which extends from the bottom of the member 295 upwardly to the dottedl line 392. There is a slot 295 aligned with each of the holes and plungers 293. The intersection between each of the slots 225 and its respective hole 29? forms a seat below which the lower end of plunger 298 will not move. A trunnion receivpcrtion 329 is provided on each side of the lock 255 at the lower end of an arcuate surace The one arcuate surface Si@ is slotted ,for facilitating the assembly of the actua- This assembly is accomplished by loing the trunnion within the slot 3l i there- Jy permitting the trunnion 327 on the opposite end ci the actuator 302 to clear the shoulder 3 l2 of body 295 and become seated in its trunnion receiving portion 359. Seating of the trunnion 253'? adjacent the shoulder SI2 locates the opposite trunnion 325 beyond the slot 3l l so that it is urged downwardly to its trunnion-receiving by the action of the spring-pressed plunger 292. As shown in Fig. 8, a slight clearance rovided between the trunnions 302, Bill and the arcuate walls 399. This clearance is al- 1.6 of .switches .2.52 that can be located within .a given space.

.Spring conductors .3l 3 are provided alternately on each side of the insulating member 25| such that their free ends overlie the tops oi the holes 295 with-in which the `portions 299 of the plungers 29S are located. Each of these free ends of the conductors 3.!3 is provided with a hardened steel contact portion 3M directly over the holes 296. The spring 3l3 resiliently urges this contact firmly into engagement with the top of the rigid body member 25l. A slight clearance is provided between the top of the stem portion 299 and the hardened steel contact 3 l 2. The fixed end of each conductor 3 l 3 is connected to one of the lwires 254 to Ztl that lead to the distributor 264.

Each of the actuators 322 is provided with a depending portion 3l5 that extends downwardly to a point where it will engage either side of the dog 253. An abutting engagement between the portion 3l5 and either face of dog 25.3 always occurs totally within a surface that is at right angles to the direction of relative movement between .the dog 253 and switch 252. Accordingly, slight transverse movement of dog 253 relatively to the direction of the relative movement between it and switch 252 does not affect the point at y which contact vbetween 3 ill and the upper end of stem 299 occurs. Engagement between 3l5 and dog 253 in any other manner will introduce detrimental inaccuracies to the apparatus. Movement of the block 25B rightwardly as shown in Fig. 8 will cause the actuator 392 to pivot about the trunnion 9d? adjacent shoulder 3l2 causing the ways taken up, as evidenced in Fig. 3 by the absence ci clearance about trunnion 397i, before the switch 252 is operated by dog 253.

rihe construction and arrangement of the parts oi the switch 252 and its attending parts are such that a great number oi switches 252 can be located within a minimum of space. lThe relatively thin, flat plates 392, together with the overall length of the trunnions 3ST extending on both of its sides, need not exceed the maximum diameter of the plunger 298 whereby the only limitation on spacing of switches 252 is the necessary wall thickness between bores 297. In the present embodiment, the plungers .298 are located on t inch diameters, which gives some idea of the number arcuate surface 2123 to force the plunger 298 upwardly against the action of spring 399. Upward movement of the plunger 298 causes abutting contact to be established between the contact 3M and the top of the stem 299, thereby grounding the circuit including the conductor 251i through the ground C. Accordingly, no wiping action betweencontact 3l@ and the top of stem 299 occurs which, therefore, eliminates all wear between said contacts. Continued movement of the member 25! rightwardly permits the free passage 0i the unit over the dog 253 without aiecting the operability of the switch because spring 393 yields and always returns contact 3M to its initial position in firm contact against the rigid body 25E. Since the construction of the trunnions 595, 39'! and the surfaces 3l@ are identical, movement of the member 251 leftwardly after it has passed the dog 253 causes depending portion SI5 to engage dog 253 well within the surface of its righthand side and, therefore, causes an identical action of the switch 252, as previously described.

As previously stated, switches 252 consume very little space. In order that the combined unit including all switches 252 and dogs 253 will occupy a minimum of space, the micrometer adjusting means including the nuts 299 and the resiliently mounted wires 286 alternate in position 'with the fixed wires 285 in adjacent dogs 253. By this means, succeeding sets of wires 295, 286 can be located so close to each other that their respective adjusting mechanisms overlap.

There are as many switches 252 including plungers 298 and actuators 302 as there are switch-trip supporting means 238 to 245 inclusive; and there are as many switches 229, identical with switches 252, as there are switch-trip supporting means 229 to 23;l inclusive. All of these switches 252 and 229 are identical, as well as each of the switch-trip supporting means.

Referring to Fig. 12, the turret head Ht includes a turret 316 adapted to support a plurality of tools for movement into and out of engagement with work. The turret 316 is mounted for rotation on a stud 311 fixed to the slide 29. Normally the turret 316 is rigidly locked to the slide 29 and it is adapted to be power driven by a motor 318 fixed on the slide 29, all in the manner shown and described in application Serial Number 443,992, filed May 21, 1942, in the name of Edward P. Bullard, III, et al. now Patent Number 2,384,809, issued September 18, 1945. The turret 316 is adapted to be controlled from the function drum 110 by a double pole switch 319. The line L2 is connected to one pole of the switch 319 and the corresponding pole thereof is connected by a conductor 320 to one side of the motor 318. The other side of said motor is connected to the line L1. Usually, the turret 316 is indexed to present different tools to the work when no other movement of the slide 2S is being made. Accordingly, one of the index positions of the drum 119 is consumed by the function of indexing the turret 316. According, at the conclusion of the indexing of the turret 316, it is necessary that the drum be indexed to its next succeeding position in order to continue the cycle of operation. This is effected by the second portion of the switch 319. One pole of this second portion of switch 319 is connected to a conductor 32| that is connected to one side of a double pole switch 322. The corresponding pole of this switch is grounded. The' corresponding pole of the second portion of switch 319 is connected to a conductor 323 that is in turn connected to the conductor 212 leading from the distributor 264. From the foregoing, it is evident that the placing of a dog on drum 110 in position to close switch 319 will, when effective, energize the motor 318 starting the indexing of turret 316. A disc 324 attached to the indexing mechanism for the turret 316 makes a single revolution during the indexing of turret 316 from one position to another. Near the completion of the revolution of disc 324, a cam 325 thereon closes switch 322 providing a ground connection through it, the conductor 321, the second portion of switch 319, conductor 323, conductor 212, switch 214, switch 216, conductor 218, source of energy G and solenoid 219, thereby operating valve 216 and indexing the drum 116. Ordinarily, upon the indexing of drum 110, switch 319 opens leaving switch 322 closed and in an improper position for subsequent indexing of the turret 316. However, the switch 322 also includes a portion 326 which is closed when cam 325 is effective. The closing of the portion 326 provides a circuit including line L2, conductor 321, the portion 326 of switch 32 2, conductor 32B, motor 318 and line L1, continuing the rotation of the disc 324 until the cam 325 passes beyond its effective position relativeV to switch 322 effecting opening of the latter.

Often, the work to be performed by the machine utilizes less than the total number of longitudinal series of holes 11| on the drum 110 and before a succeeding cycle may be employed, the drum 110 must be indexed back to its starting position. This is accomplished in the present invention by providing a switch 329 in line with one of the circumferential series of openings 111. The one pole of switch 329 is grounded, while the other pole is connected to conductor 212 as previously described. Accordingly, a dog on drum 110 in line with switch 329, when effective, will form a circuit fromv the ground through the switch 329, conductor 212, switch 214, conductor 212, switch 216, conductor 218, source of energy G and solenoid 219, which circuit will operate the valve 210 to effect indexing of the drum 111).`

The machine to which this control mechanism is applied is adapted manually to be operated independently of the automatic control. Furthermore, during the setting up of the machine, it is desirable to cause it to stop at the completion of any function. Additionally, in the event anything occurs which might damage the machine, it is desirable to stop the machine instantly. These three conditions, as well as a fourth condition of automatic run, are each rendered effecf tive by the operation of a single, manually-operable control lever 330 rigid on a shaft 331, shown in section, and the length of which is represented by the center line 332. In the position shown in Figure 12, the apparatus is set for automatic run such that a cycle of operation set up on the drum 119 will automatically be performed by the successive indexing of the drum which will occurV only upon the completion of the last preceding function. The extent of each function is determined by the adjustment of the dogs 253 on the supporting means 229 to 236 and/or 238 to 245, both inclusive. Movement of the hand lever 330 to the position 333 will move the valve 213 to interrupt communication between lines 212 and 214. Upon the completion of the function being performed, energization of the solenoid 219 will operate the valve 210 to neutralize the operating structure of the apparatus through the action of the valves 221, but the drum 119 will not be indexed because of the interruption of the flow of iiuid under pressure from line 212 to line 214. Movement of the hand lever 336 to the position 334 will cause a cam 335 on the shaft 331 to close a switch 336. One pole of the switch 336 is grounded and the other pole is connected to the conductor 218. Upon closing switch 336, the solenoid 219 is energized and the interruption between lines 212 and 214 is still effective. Accordingly, the machine instantly stops since r energizing of the solenoid 219 operates the pistons 221 to exhaust the operating parts of the machine tool.

Movement of the hand lever 339 to the position 331 of Fig. 12 operates the valve 121 so that line is connected to an exhaust 338 through the undercut portion 339 of said valve. This exhausts all the neutralizing mechanisms including that for the reversing clutch 49, the drop worm 36, the traverse arm 16 and the traverse arm 69. It also exhausts the line 128 such that all of the valve plungers 131 to 144 descend out of operative position so that the drum 110 may be indexed without causing operation of the machine. Additionally, movement of the handle 339 to the position 331 will operate valve 213 so that communication will be established between the line 212 and the line 214. Finally, with the hand lever 339 in the position 331, the cam 335 opens the lower portion of switch 214 and closes the upper two portions 214 and 214". The portion 214' includes one pole that is connected to a push-button switch 339. The opposite pole of portion 214 is connected to conductor 212. The opposite pole of push-button switch 339 is grounded. Accordingly, with handle 330 in position 331, closing push-button switch 339 will establish a circuit from ground through switch 339', portion 214', conductor 212, switch 216, conductor 218, generator G, solenoid 219 to ground, causing operation of valve 219 to index drum 'a-caves 19 without, however, supplying fluid under pressure to valve body |29.

The other portion 273" of switch 214 is in av circuit includingY a conductor 340 that is joined to line L2. The other branch of this circuit comprises a conductor 313|, a push-button switch 342 and another conductor 333 that is connected to motor 3|8 forming with line L1 a complete circuit for said motor. Accordingly, with the lever 330 inthe position 331 of Fig. 12, the entire machine may be operated manually by the hand levers previously described in connection with Figs. l, 2, 6 and 7'. The turret 3ft may be indexed at the will of the operator by simply closing the pushbutton switch 332, and the function drum |10 may be indexed step by step by closing'the pushbutton s witch 333.

Operation In Yloro'ler to better understand the principles of operation of the invention, a very simple cycle of operation of the apparatus will be described. Referring to Figures l5 to 18, the turret head Ht is provided with four tools 333, 335, 336 and 31W, one at each station of the turret. The work piece 333 is adapted to be machined by turning it to a specific diameter, rough facing the top, finish facing the top, and boring a hole centrally of the work. In setting up the apparatus, the

first thing to do is to determine the successive functions required to produce the completed work and to attach dogs lf2 at the correct locations in the successive longitudinally-disposed'rows of holes il on drum lf'i to cause said functions successively to be performed by the apparatus.

Referring to Figures to 18, inclusive, the successive functions required to machine the work 343 are as follows:

1. Traverse turret 3| inwardly from a starting point.

f 2. Feed said head inwardly at a pre-determined rate in order to properly locate the tool 341i to turn the work 3&3 to a specific diameter.

3. Traverse head 3|,6 downwardly to a point slightly above the work 333,. 4. Feed the head downwardly at a desired` rate in order to turn the work to size.

5.. Traverse the turret outwardly.

5. Traverse the turret upwardly.

7. Index head 3m so that tool 343 is located in working position.

8. Traverse inwardly until tool 345 is spaced lslightly outside of the periphery of the work.

9. Traverse downwardly until the tool 345. is located slightly above the work.

10. Feed downwardly to locate tool 345 for making the rough facing cut.

11. Feed inwardly to face the top of the work 12. Traverse upwardly.

lf3. Index turret 3 i E to bring tool 343 into working position.

14. Traverse downwardly to a point slightly abovefthe work 333.

15,. Feed downwardly to size.

16. Feed outwardly, producing the finish cut on thetop o f the work 338.

17. Traversevupwardly.

18. Index the turret to bring the drill 331. into working position.

19. Traverse inwardly until the drill 34.1: is near the center of the work piece 338.

20. Feed inwardly to accurately locate the drill 31551 at the center of the work piece 3128.

2d 2l. Traverse downwardly until the drill is slightly above the work.

22. Feed downwardly to drill' the hole 349. 23. Traverse upwardly. 24. Traverse outwardly to substantially the original starting position.

25. Index the turret 316 tov bring the original tool 344 into working position.

26. Index the drum |10 from station to station until the last station is reached.

Figure 20 discloses the d-rum |13 in developed form having dogs |12 located at various stations to produce the above-listed functions in sequence. For example, the tenth function to be performed requires feeding the turret head downwardly to size at a proposed feed identified as the #t3Y feed.`

Accordingly, dog |12 is located in the tenth space of drum |10 beneath the index, clutch L30 for out or down feed a dog |12 is also located beneath the index, form 36 for up or down feed; a dog |12 is located beneaththe index, feed 3; and a dog |12 beneath the index, feed A. These four dogs |12 located in the tenth space on the drum |13 will cause the turret head 3H; to move downwardly at a feed rate designated as feed 3. The dog beneath the index feed A is necessary to move the keyl 38 into engagement with the gear d5. Absence of a dog beneath the index feed A means that the key 43 is in en gagement with the gear 45.

The twenty-sixth space of the drum |10 andy every space thereafter to, but excluding thev fortieth, includes a single dog beneath the in-v dex, drum index. This causes the drum |10 to automatically index from station to station at the conclusion of the automatic cycle operation to the last station of the drum where it comes to rest, thereby arranging the drum |10 inposition to begin a new cycle of operation by merely depressing the starting switch 26.9 (Fig. 12).

Figure. 19 discloses in enlarged' form, the switches 249, 252 and the arrangement of the adjustable dogs 253 on the switch-trip supporting means 229 etc., and 238, etc. With the drum |10 pre-set with the dogs |112. as. just described, the work 348 chucked tov the table W and the drum |13 at its last or fortieth station, the operator places the handle 33|) (Fig. l2) in the position shown in solid lines and closes starting switch 269. Closing switch 233A energizes solenoid 213 actuating valve Elli, causing drum |10 tobe indexed to the No. 1 station containing the dogs for effecting inward traverse movement of the turret head 3|6. When the tool head has traversed inward-ly to a point a short distance fromv the outer peripheral edge of the Work, the operator moves the hand lever 330 tothe position 334 whereupon the head 3|6 instantly stops. A dog 253 on the supporting means 235 is then adjusted relatively to the switch 252 aboveit such that the switch 252 will close slightly before the head reaches the desired poi-nt. This leeway is-provided in traverse movement to compensate for the over-travel due to the highrate of speed of the head.

The operator then moves the hand lever 330 to the position 331 rendering theA apparatus capable of manual operation. Referring to Fig. 1, the traverse hand lever 'il is then moved to the right, causing the headV Ht to traverse outwardly away from the work. The operator then moves the handle 33! to the position 333 causing the turret head Ht to move inwardly at traverse speed until switch 232 is operated, whereupon head Hf; stops, but the drum is not indexed to its station No. 2 because position 333 of handle 330 is automatic stop which permits neutralizing the apparatus but prevents indexing of drum |10. This permits the operator to make sure that the head will stop at the point he wishes. Movement of the hand lever 330 to the solid line position shown in Fig. 12 instantly causes indexing of the drum |10 to the No. 2 station which contains dogs |12 causing feeding of the turret 3|6 inwardly at the No. 1 feed rate. This is permitted to continue until the tool 344 has moved to a point where its cutting tip is within the boundary of the work 348 suiiciently to perform a machining operation, at which point the handle 33D is moved to the position 334 causing instant stopping of the feeding movement of the turret. The extent of this inward feed should always be less than the nal amount necessary to machine the work to size. That is, the initial cut should produce oversize work rather than undersize work. A dog 253 on the No. 2 supporting means beneath a switch 252 is adjusted so that its right-hand side contacts the left-hand side of the depending element 3|5 of switch 252 (Fig. 8).

The hand lever 330 is then positioned in the solid line position of Fig. 12 whereupon the drum |10 instantly indexes to the third station at which dog |12 is located for effecting downward traverse movement of the head Ht. This downward movement is continued until tool 344 is a small distance above work 348 at which time the handle 330 is moved to the position 334, thereby instantly stopping the downward movement of the tool 344. The adjustable dog 253 on the support No. 3 beneath a switch 249 is then adjusted s0 that it has just effected closing of the switch 249. Lever 330 is then moved to the position 331 and the handle 12 (Fig. l) is moved leftwardly causing upward traverse movement of the turret 3|5 a short distance. Handle 330 is then placed in position 333, Fig. l2, whereupon the head Ht moves downwardly in traverse speed until switch 249 is closed by the dog 253 on the support No. 3 therefor, at which time the head Ht stops and the function drum |13 does not index. This permits the operator to check the point at which the head Stops its downward traverse movement.

The hand lever 330 is then moved to the solid -line position shown in Fig. l2, whereupon the drum |13 instantly indexes to its fourth station containing dogs |12 which effect downward feeding of the tool 344 at the No. 3 speed rate. This downward feeding causes actual machining of the work 348 and is continued a desired amount, at which point the operator moves the handle 33|! to the position 334, causing instant stopping of the head Ht. A dog 253 on the No. 4 supporting means beneath the switches 249 is then adjusted to effect closing of the switch 249 and locked in position. The head Ht is then raised a slight amount and the handle 330 is positioned at point 333, Fig. l2, causing downward feed of the tool 344 the desired amount at which time the head Hr. stops, but the drum |19 is not indexed to the next station. At this point, the operator accurately measures the diameter of the work 348 which has been machined by the down ward feed of the tool 344. Usually, it is necesu sary to remove additional metal from the work 348 to produce the exact diameter required. The operator must then move the dog 253 on the No. 2 support under the switches 252 to the left an amount equal to one-half the difference between the actual diameter of the work and the desired diameter. This is accomplished by turning the micrometer head 299 (Fig. 8) in the correct direction. As previously described, the micrometer head 290 is provided with 4G threads per inch that mesh with the threads 289 on the rod 286. Accordingly, one revolution of the head 29) will cause 1/10 of an inch movement of the rod 286 and with it the dog 253. A dial is provided for each of the heads 293 that will permit very ne adjustments of the dog 253 similar to the operation of a micrometer. Having made this adjustment, the lever 339 is positioned in the position 331 in Fig. l2 and the head Ht is moved upwardly and outwardly to a point near the starting point. The push-button switch 339 is held closed causing the drum |10 to be rapidly indexed from station to station until it reaches its last station, when the lever 330 is returned to its solid line position in Fig. 12 and the starting button 269 is closed, whereupon the head Ht traverses inwardly; then feeds inwardly to the new adjusted location; traverses downwardly; and feeds downwardly to perform the adjusted machining operation. While the adjusted machining operation is in progress, the hand lever 33B is moved to position 333 so that upon its completion, the head Ht will stop, but the drum '|19 will not be indexed to its next station. The operator may then accurately measure the diameter of the work, and if further adjustment is required or further removal of metal is required, the previous procedure is employed until the work has been accurately machined to size.

Assuming that the diameter of the work 348 is accurate, the lever 330 is moved to its solid line position in Fig. 12 causing the drum |19 to index to its fifth station containing ardog 12 located in position to cause outward traverse movement of the head Ht. `When the head Ht has traversed outwardly sulliciently so that the tool 344 adequately clears the work, the operator moves lever 33B to the position 334 instantly stopping the movement of the head Ht. The dog 253 on the fifth support beneath a switch 252 is then adjusted so that it closes the switch 252 above it, whereupon it is locked in position on the support. The hand lever 330 is then moved to its solid line position causing instant indexing of the drum |1 to station No. 6 containing a dog 12 that eiTects upward traverse movement of the head Ht until the tool 344 is sufciently above the work 348, so that upon indexing the head Ht the tool 345 will not interfere with the work 348. At this point, the hand lever 39 is moved to the position 334 instantly ,stopping the upward traverse movement of the head Ht. The dog 253 on the No. 6 support beneath a switch 249 is then adjusted to eiect closing of the switch 249 above it and the dog is then locked in position on its support. The hand lever 330 is then moved to its solid line position in Fig. l2, causing instant indexing of the drum E10 to its station No. 7 at which a dog |12 is located for effecting the indexing of the turret Ht, whereupon the tool 345 is moved into position to effect further work on the work piece 348.

The procedure just described is carried out until all operations as dictated by the setting of dogs |12 on the drum |10 have been completed. Should the number of functions be less than the number of stations of the drum |10, the remaining stations contain dogs |12 beneath the drum indexing switch 329 (Fig.' 12) so that at the conclusion of the operation of the Werl;

348, the drum is indexed to the last station thereoi, setting the apparatus in condition to repeat the operation on a succeeding Work piece.

After the apparatus has been set as above described, it is only necessary to remove the finished work piece, replace it with a rough piece, chuck it to the table W and close the starting switch 269 (Fig. 12). The Work piece 3:13 is then completely and accurately machined in accordance with the pre-*determined cycle of operation, and the apparatus comes to rest upon the completion of the machining thereon.

Although the various features of the improved control mechanism have been shown and described in detail to fully disclose one embodiment of the invention, it will be evident that numerous changes may be made in such details, and certain features can be used Without others, without departing from the principles of the invention. v

What is claimed is:

1, In a machine tool including a movable member, means for moving said member; an electrical circuit comprising in series arrangement, a source of voltage; an operating means adapted to be energized by said source of voltage for rendering ineffective said moving means; contact means adapted to'be closed at any desired 'rate by the action of said movable member for energizing said circuit to thereby render effective said operating means; and other contact means adapted to be opened incident to the action of said operating means for de-energizing said circuit While said inst-mentioned contact means remains closed.

2. In a machine tool including a movable member, means for moving said member; an 'electrical circuit comprising 'in series 'arrangement, a source of direct current; an operating means adapted to be energized by such source of direct current for rendering ineffective said moving means; contact means adapted to be closed at any desired rate by the action of said lmovable member for energizing said circuit to thereby render eiective said operating means; and other contact means adapted to be opened incident to the action of said operating means for de-energizing said circuit while said rstmentioned contact means remains closed.

3. In a machine tool including a movable member, means for -moving said member; an electrical circuit comprising in series arrangement, a source of voltage; operating means adapted to be energized by said source of voltage for rendering ineffective said moving means; an electrical distributor including a plurality of contacts, one for each point within a cycle of operations of said movable member at Which said member is adapted to be stopped, and an arm adapted to be indexed from position to position for successively connecting said contacts into said series circuit; a plurality of contact means adapted to be closed at any desired rate by the action of said movableimember for energizing said circuit, at least one of saidV contact meansbeing provided for each of said distributor contacts, and each adapted-successively to be connected into said Vseries circuit simultaneously with its corresponding distributor contact; and

--means for moving said distributor arm from one -contact to the next succes ing contact upon the closing ofthe contact means for saidone contact thereby to cie-energize said'series circuit While Cil said contact means for said one contact remains' closed.

4. In a machine tool including a movable member, means for moving said member; an electrical circuit comprising in series-arrangement, a source of voltage; an operating means adapted to be energized by ysaid source of lvoltage for rendering ineffective said moving means; an electrical distributor including a plurality of contacts, one for each point within `a cycle of operations Vof said movable member at which said member is adapted 'to be stopped, and an arm adapted to be moved from yposition to position for successively connecting said contacts into said series circuit; a plurality of Vsets ofcontact means each set including a plurality of contacts arranged in parallel relation relatively to each other, and at least one set being provided -for each of said distributor contacts, `and each -contact being adapted to be 'closed at any desired rate by the action of said movable member for energizing said vseries circuit; and means `for moving 'the arm of said distributor from one of its contacts to its next succeeding contact upon the closing of any of said parallel arranged contacts corresponding to said one contact to thereby de-energize said circuit While said parallel arranged contact for `said one contact remains closed.

5. Apparatus comprising in combination, a member; vmeans for causing said member to perform a plurality of functions; 'means adapted to be indexed from station to station and adjustably to be pre-setto cause said member to 'perform a plurality of functions within a cycle of operation; 'an electrical circuit including in series arrangement, a source of voltage; an operating means adapted to be energized upon energization of said series circuit for causing said pre-settable means to be indexed from one station to its next succeeding station; an electrical distributor including'a plurality of contacts, one for each station to which said indexable means is adapted to loe-moved, and an arm adapted to be indexed from I Contact to Contact for' successively connecting the distributor contacts into said series circuit; a lplurality of adjustable contact means, one for each of said'distributor contacts and each adapted to be closed at any desiredrate by the action of said function performing member for-'energizing said series circuit to thereby energize said operating'means; and means for moving the distributor'arm'from oneo'f its contacts to its next succeeding contact 4vvhen the contact means corresponding to said one contact of said distributor is closed for deenergizing said series circuit While said contact means for said one 'contact of said distributor remains closed.

6. Apparatus comprising in combination, a member; means for causing said member to perform aplurality of functions; means adapted adjustably to be pre-set to cause said member successively'to perform a plurality of functions Within a cycle of operation; an electrical circuit including in series arrangement, a source of voltage; a distributor having a plurality of contacts, one for each function withinsaid cycle of operation, and an arm adapted to be moved from contact to contact for successively connecting said distributor contacts into said series circuit; a

frame; a plurality of supporting means mounted in said frame, one for each of said distributor contacts; dog means adjustably attached to each of-said supporting means; a plurality of contact means, one for each of said dog means and eaCh located in cooperating position relatively to its, dog means; means for providing relative motion between said plurality of contact means and said frame in proportion to the movement of said member for causing said adjustable dog means to close their corresponding contact means; and means for moving said distributor arm from one of its contacts to its next succeeding contact upon closing of the contact means for said one contact of said distributor for de-energizing said series circuit while said contact means for said one contact of said distributor remains closed.

7. In a machine tool including a movable member, means for moving said member; an electrical circuit including in series arrangement, a source of voltage; contact means; means operable by the action of said movable member for closing said contact means to energize said circuit; means operated by the energization of said circuit for rendering ineffective said moving means; and means for de-energizing said circuit prior to opening said contact means.

8. In a machine tool including a movable member, means for moving said member; an electrical circuit comprising in series relation, a source of direct current; electrically-operated means adapted upon energization of said circuit to render ineffective said moving means; contact means; means operated by the action of said movable member for closing said contact means at any desired rate to energize said circuit; and means for de-energizing said circuit while said contact means remains closed.

9. In a machine tool including a movable member, means for moving said member; an electrical circuit comprising in series relation, a source of voltage; electrically-operated means adapted upon energization of said circuit to render ineffective said moving means; contact means; means operable by the action of said movable member for closing said contact means at any desired rate for energizing said circuit; and means for de-energizing said circuit and operable byV said electrically-operated means While said contact means is closed.

10. In a machine tool including a movable member, means for moving said member; means for Vrendering ineffective said moving means to thereby effect stopping of the movement of said member; an electrical circuit comprising in series relation, a source of voltage; a plurality of contact means; means for successively connecting and disconnecting said contact means into and from said series circuit; means operable by the action of said movable member for closing each of said contact means for energizing said circuit when it is connected into said circuit; and means for operating said connecting and disconnecting means to include the next succeeding contact means in said circuit and to exclude therefrom said last preceding contact means while it remains closed.

11. In a machine tool including a movable member, means for moving said member; an electrical circuit comprising in series relation, a source of direct current; a plurality of contact means; means for successively connecting and disconnecting said contact means into and from said series circuit; means operable by the action of said movable member for closing each of said contact means for energizing said circuit when it is connected into said circuit; means operable upon energization of said circuit for rendering ineective said moving means; and means for operating said connecting and disconnecting 26 means prior to theopening of the contact means that energized saidV circuit. Y

12. In a machine tool, atool support adapted tobe moved along a path for performing a metalworking operation means for moving said tool support along said path; electric-contact means adapted upon being closed to render ineffective said moving means; a resiliently-mounted support; a member mounted .on said support and adapted adjustably to be fixed thereto; a micrometer attachment associated with said vsupport to accurately adjust the position of said member in space; and means for providing relative motion between said member andsaid electric-contact means proportional to the movement of 'said tool support for causing cooperation between said member and said electric-contact means to render ineffective said moving means.

13. In a machine tool, a tool support adapted to be moved along a path for performing a metalworking operation; means for moving said tool support along said path; electric-contact means adapted upon energization to render ineffective said moving means; a supporting rod; a frame for holding said supporting rod; a member releasably Xed to said supporting rod; a micrometer head threaded to one end of said rod and adapted to abut against said frame; resilient means normally urging said micrometer head against said frame; means for providing relative movement between said electric-contact ,means andsaid frame proportional to the movement of said tool support; and meansr for energizing said electriccontact means by the cooperation between itV and said member for rendering ineffective said `moving means. v 14. In a machine tool, ya-tool support adapted to'be moved along a path for performing a metalworkingoperation; means for moving said tool support along said path; a. device adapted ,upon operation; to render ineifective said moving means ;,a frameya fixed guide-rod mounted in said frame; 'av member slidably mounted on said fixed` guide-rod; another rod in said frameex tending throughsaid member; means for releasably xing'said member to said other rod; a micrometer lhead threaded to one vend. of said other rod and adaptedr to abut against said frame; resilient means normally urging said micrometer-head against said frame; and means providing relative movement between said device and said frame in proportion to the movement of said tool support, whereby said member will -operatesaiddevice to render ineffective said moving means.- Y Y Y Y 15. In a machine tool, a tool support adapted to be Vmoved along a path a plurality of `times within a cycle of operation for performing metal- 4working operations on work; means for moving said tool support along said path; a plurality of devices each adapted to vbe operated for rendering ineffective said moving means; a plurality of resiliently mounted supports, one for each ofr said plurality of devices; a member slidably mounted on each of said supports in abutting alignment relatively to its vcorresponding device and adapted adjustably to be fixed thereto, adjacent supports adapted to pass through their members at different locations; a micrometer attachmentassociated with each of said supports `for accurately adjustingy the position of said members in space; `and means for providing relative movement between said devices and said members proportionally to the movement of said 2T? tool support, whereby said devices are operated to render ineective said moving means.

16. Apparatus comprising in combination, a member; means for causing said member to perform a plurality of functions; means adapted adjustably to be pre-set to cause said member to perform a plurality of said functions in any order in a cycle of operation; means for terminating each of said functions; an electrical circuit including in series arrangement, a source of voltage; an operating means adapted to be energized upon energization of said series circuit for rendering effective said function-terminating means; contact means adapted upon being closed to energize said circuit; means responsive at any point within each of said functions for closing said contact means; and other contact means within said series arrangement adapted to be opened upon energization of said operating means.

17. Apparatus comprising in combination, a member; means for causing said member to perform a plurality of functions; means adapted adjustably to be pre-set to cause said member to perform a plurality of said functions in any order within a cycle-of operation; means for terminating each of said functions; a support; an element releasably fixed to said support; means for accurately locating said element by adjusting said support; an electrical circuit including in series arrangement, a source of voltage; an operating means adapted to be energized upon energization of said series circuit for rendering effective said function-terminating means; contact means adapted to be vclosed by the action of said element at any point throughout the extent of the functions of said' member for energizing said circuit; and kanother contact means adapted to be opened by said operating means for de-energizing said circuit while said first-mentioned contact means remains closed. Y

18. Apparatus comprising in combination, a member; means for causing said member to perform a pluralityof functi-ons; means adapted adjustably to be pre-set to cause said member successively toA perform a plurality of said functions within a cycle of operation; means for terminating said functions; a frame; a plurality of supporting means mounted in said frame, one for each function to be performed within said cycle ,of operation; an element adjustably attached to each of said supporting means; an electrical circuit including in series arrangement, a source of voltage; a plurality of contact means, one for each of said elements, each located in cooperating position relatively to its element and each adapted upon being closed to energize said circuit for rendering effective said function-terminating means; a distributor including a plurality of contacts, one for each of said contact means, and an arm adapted to be moved from position to position for successively connecting said distributor contacts and their corresponding contact means into said series circuit; means for providing cooperation between said elements and said contact means by the action of said membergwhereb'y the contact means that is connected into said circuit is closed by its corresponding element' to energize said circuit; and

means formoving said distributor arm to its next succeeding contact'V upon energization of said circuit While the contact that was closed to energize saidcircuit remains closed.

' 19. Apparatus comprising in combination, a member;v means for moving said member in either direction along a plurality of paths; means adapted adjustably to be pre-set to cause said member to be moved in either direction along said paths a plurality of times within a cycle of operation; an electrical circuit including in series arrangement, a source of voltage; an operating means adapted to be energized upon energization of said series circuit for rendering ineffective said moving means;a plurality Q SQS of parallel arranged contact means each setincluding a contact for each path of movement along which said member is adapted to be moved, and a set for each movement of said member along said paths within said cycle of operation; a distributor including a plurality of contacts, one for each set of the parallel arranged contact means; an arm for said distributor adapted to be moved from position to position for successively connecting said distributor contacts and their corresponding sets of parallel arranged contacts into said series circuit; means movable in proportion to the movement of said member for closing the contact means that is connected into said series circuit thereby to energize said circuit; and means rendered effective upon energization of said series circuit for moving said distributor arm to its next succeeding contact to cle-energize said circuit While the contact that was closed to energize the circuit remains closed.

20. in a machine tool, a tool support adapted to he moved along a path a plurality of times within a cycle of operation for performing metalworking operations; means for moving said tool I support along said path; an electrical circuit including in series arrangement, a source of voltage; an operatingmeans adapted to be enerupon energization of said circuit for rendering ineffective said moving' means; a plurality of'electrical switches one for each movement of said tool support within said cycle of operation, each switch including single contact means and contact-closing means; a frame; a plurality of supports mounted in said frame, one for each of said switches; a member slidab'ly mounted on each of said supports; means for releasably fixing said members to their supports in cooperating position relatively to their respective electricai switches; means for providing relative motion between said switches and said frame; and means for rendering a switch effective for each succeeding movement of said tool support within said cycle of operation.

21. In a machine tool, a tool support adapted to be moved along a path a plurality of times within a cycle of operation for performing metal-working operations; means for moving said tool support along said path; an electrical circuit including in series arrangement, a source of voltage; an operating means adapted to be energized upon energization of said circuit for rendering ineffective said moving means; a plurality of electrical switches one for each movement of said tool support within said cycle of operation, each switch including single contact means and contact-closing means; a frame; a plurality of supports mounted in said frame, one for each of said switches; a member slidably mounted on each of said supports; means for releasably fixing said members to their supports in cooperating position relatively to their respective electrical switches; means for providing relative m0- tion between said switches and said frame; means for providing an abutting engagement between said members and the contact-closing means of their respective switches within a surface that 

